DSO5102P Rotary knobs not working

user567121 · Post time 2020-8-23 23:28:16

Edited by user567121 at 2020-8-23 23:31

Shoey replied at 2020-8-13 20:41
Has anyone else been able to fix this fault? Seems to be a recurring issue, several threads about th ...

Hi all, any news on the rotary knob problem?? i got a dso5102p which was barely ever used and now i got no working knobs, sometimes just sumtimes one or two knobs (ChA or trigger) are working a bit but not accurate. Second issue i have is that i cannot update firmware since recent version from their page is not accepted. Error: 0xfe
my versions are sw: 3.40.0(180120.0) and hw: 1010xffff8108

user567121 · Post time 2020-9-6 18:30:27

Edited by user567121 at 2020-9-6 18:36

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user567121 · Post time 2020-9-6 18:31:13

Edited by user567121 at 2020-9-6 18:36

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user567121 · Post time 2020-9-6 18:32:27

Edited by user567121 at 2020-9-7 02:37

Thank you, i solved the usb format problem, the new firmware runs ok, the self calibration passes without errors (most of the time) BUT the knob problem still exists, knobs rotation works ~ 5% of the time, it doesn't feel like a bad contact
btw, i tried it multiple times to trigger the cause like a bad contact on the keyboard or bad connecteion on the cable, i have reflowed almost any solder point of any large part like mentioned on the U1 ic and more. The problem behaviour is still 100% the same (my greater fear was it could fail complete but the soldering was lucky)
What could be the cause? Interferences? They work just to fail seconds later without rebooting or barely touching it... I can't look it's own signals with only one scope..

Any Ideas?
Are there spare parts availible for a good price? Frontpanel/cable?
thank you very much for any help

SORRY for tripple-posting... site was stuck in loading

user567121 · Post time 2020-9-12 02:10:44

Edited by user567121 at 2020-9-14 06:16

wangshuang replied at 2020-9-8 15:59
You can contact seller for a new keyboard.

he may be dissapeared since his ebay shop is empty he is gone i guess in my case, anyone else supplying spare parts?

user567121 · Post time 2020-10-19 00:23:33

Edited by user567121 at 2020-10-20 04:25

Znida replied at 2020-10-10 17:00
I fixed it. I desoldered all the diodes to the knobs and added them back one by one. It was a faulty ...

good to hear that you solved it

Is it 100% fixed for you now?

I will resolder and investigate mine too. Was it perfectly working after you made one knob (the faulty one) inactive by desoldering its diode and this defective knob was suppressing all the other knobs? You say you did it other way round, you desoldered all diodes and put them back one by one and suddenly all began to fail. right?

And the source of evil was the knob itself you say..? but there was nothing strange with it..

Hope i can trace my error the same way down to a rotary knob. If you had the same faulty behavour like mine before then i think chances are good. (mine fails most of the time complete on all knobs, buttons also don't work, sometimes out of nothing they work perfect for a couple of seconds or minutes just to fail completely and won't get back to good, or only for a short time - i did a resolder on almost every part and connector and tried to check the keyboard cable etc..no changings, haven't try to investigate signals of the knobs itsef which would be interesting i think (i'm no expert in this, more general electronics) but because measuring the board without another oscilloscope on an open case and a mirror makes you crazy in no time)

hope the best, regards

user567121 · Post time 2020-12-9 00:10:22

Edited by user567121 at 2020-12-9 01:45

i removed the tiny diodes from the knobs, after the second knob, the V/DivCh.A-Knob in my case it worked for longer time without errors, so i soldered back all diodes except for the faulty V/Diff(ChA) Knob and it is working good. Now i will dissable the knob and look inside and maybe i will look for a replacement. My rotary encoder is shortend to gnd at one of its three pins (unlike all other encoders on the board)

thanks for your all the help, i will tell if it is fixed complete

Update: fixed - it was the knob (rotary encoder) !
It had a shortcut from its metal body case to one of the three contacts. (THANKS for the info @Amy !) It was kind of cheap factory production i guess because it is a bit misterious. Inside the knob was everything okay and you can barely see it, but if you open the 4 metal clamps which holds the knob together you maybe see the problem. The main plastic body part has these integrated contacs, they are in risk that the edges of this part with contacs will touch the metal clamps if the housing is closed by bending them over.

So after i have opened the knob i closed it not so tight it was working again.

regards